In the manufacturing of integrated circuit packages (e.g., bump-on-trace laminate packages), a solder mask is used to physically and electrically insulate portions of the circuit. A solder mask generally defines the portions of the circuit where no solder or soldering is required. A solder mask comes in a variety of differing media, depending on the particular demands of the application.
Conventional methods often apply the solder mask to the underlying structure (e.g., a substrate layer, semiconductor layer, etc.) using, for example, lithographic processes, such that the solder mask is formed as a layer on the underlying structure. The solder mask layer may include openings for vias, solder bumps, conductor pads, etc. The solder mask layer generally includes one or more, or a plurality of vertical edges around the peripheral edge, defining the walls of the openings, etc. The solder mask edges may be adjacent other components of the integrated circuit package.
There is a need for an improved solder mask shape for integrated circuit packages that overcomes the aforementioned, as well as other, deficiencies in the conventional methods.